Fiber glass batts are packaged in a compressed state in order to reduce the size of the package for purposes of warehousing, shipping and handling. The packaging operation, which consists of compressing the batts to their desired thickness and encasing them in plastic or paper wrappers, is a critical process because it can affect the insulating performance of the batts. Proper compression and packaging will allow the batts to spring back to substantially their original thickness when the package is opened. Certain packaging practices, however, reduce the recovery and thereby the insulating performance of the batts. For example, when batts are packaged by moving the compressed batts into premade bags, the deleterious effect of sliding the fibers over a stationary surface damages the outside batts to the point where the batts are not able to recover enough of their thickness when they are removed from their package.
To avoid the problems caused by delivering the batts to premade bags, it has been suggested to form the package around a stack of compressed batts. In one form of such an operation the end of the packaging material has to be rethreaded through the pull rolls each time the material has been wrapped around the batts and severed. This is time consuming and tends to be a bottleneck in the packaging operation, especially in operations utilizing wide packaging film. In another method a stack of compressed batts is pushed against a stationary film which has been fed from and is still attached to a feed roll. The stack moves the film into a recess or hopper on the other side of the film so that the bottom and sides of the stack are covered by the film. The portions of the primary run of film on either side of the top of the stack are then brought together adjacent the top of the stack and heat welded to each other so that the stack is now covered on all sides by packaging film. The weld is then cut so as to sever the film surrounding the batts while still leaving the main web intact. In such an operation, however, the portion of the weld seam remaining in the web becomes a portion of the package covering the next stack of batts, so that each package contains two seams. This is not desirable since the seams represent the weakest part of the package, and the pressure of the compressed batts inside the package can sometimes cause the seams to fail.
Another important element in the packaging of fiber glass batts is the means for compressing the batts. Modern fibers are so resilient that the batts can be greatly compressed for packaging and still recover most of their thickness upon opening of the package. For example, a stack of batts ten feet in cumulative thickness may be compressed to as little as 13 inches in actual practice, and the resulting recovery of thickness is sufficient to allow the batts to function at their rated insulation value. This requires a compression means and a batt delivery means which can function rapidly and efficiently within a limited amount of space without damaging the fibers.
Obviously it would be highly desirable to provide a packaging machine and a package which are not afflicted with the prior art problems enumerated above.